Automobile accelerator pedals have, in the past, been linked to engine fuel subsystems by a cable, generally referred to as a Bowden cable. While such accelerator pedal designs varied, the typical return spring and cable friction together created a common and accepted tactile response for automobile drivers. For example, friction between the Bowden cable and its protective sheath reduced the foot pressure required from the driver to hold a given throttle position. Likewise, friction prevented road bumps felt by the driver from immediately affecting throttle position.
The mechanical cable-driven throttle systems, however, have been replaced with a more fully electronic, sensor-driven approach. With the fully electronic approach, the position of the accelerator pedal is read with a position sensor and a corresponding position signal is made available for throttle control. The sensor-based approach has been especially compatible with electronic control systems in which accelerator pedal position is one of the several variables used for engine control.
Although such drive-by-wire configurations have been technically practical, drivers have generally preferred the feel, i.e., the tactile response, of the conventional cable-driven throttle systems. Designers have attempted to address this preference with hysteresis/friction-generating mechanisms or modules in the electronic pedal assemblies which emulate the tactile response of cable-driven accelerator pedals.
In this regard, there continues to be a need for a simpler, more cost-effective, and more reliable vehicle pedal assembly with a hysteresis/friction-generating assembly.